From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?=
 <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 net/ipv4/datagram.c | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 net/ipv4/datagram.c

(limited to 'net/ipv4/datagram.c')

diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
new file mode 100644
index 000000000..90c0e8386
--- /dev/null
+++ b/net/ipv4/datagram.c
@@ -0,0 +1,123 @@
+/*
+ *	common UDP/RAW code
+ *	Linux INET implementation
+ *
+ * Authors:
+ * 	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
+ *
+ * 	This program is free software; you can redistribute it and/or
+ * 	modify it under the terms of the GNU General Public License
+ * 	as published by the Free Software Foundation; either version
+ * 	2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <net/ip.h>
+#include <net/sock.h>
+#include <net/route.h>
+#include <net/tcp_states.h>
+
+int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
+	struct flowi4 *fl4;
+	struct rtable *rt;
+	__be32 saddr;
+	int oif;
+	int err;
+
+
+	if (addr_len < sizeof(*usin))
+		return -EINVAL;
+
+	if (usin->sin_family != AF_INET)
+		return -EAFNOSUPPORT;
+
+	sk_dst_reset(sk);
+
+	lock_sock(sk);
+
+	oif = sk->sk_bound_dev_if;
+	saddr = inet->inet_saddr;
+	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
+		if (!oif)
+			oif = inet->mc_index;
+		if (!saddr)
+			saddr = inet->mc_addr;
+	}
+	fl4 = &inet->cork.fl.u.ip4;
+	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr,
+			      RT_CONN_FLAGS(sk), oif,
+			      sk->sk_protocol,
+			      inet->inet_sport, usin->sin_port, sk);
+	if (IS_ERR(rt)) {
+		err = PTR_ERR(rt);
+		if (err == -ENETUNREACH)
+			IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+		goto out;
+	}
+
+	if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
+		ip_rt_put(rt);
+		err = -EACCES;
+		goto out;
+	}
+	if (!inet->inet_saddr)
+		inet->inet_saddr = fl4->saddr;	/* Update source address */
+	if (!inet->inet_rcv_saddr) {
+		inet->inet_rcv_saddr = fl4->saddr;
+		if (sk->sk_prot->rehash)
+			sk->sk_prot->rehash(sk);
+	}
+	inet->inet_daddr = fl4->daddr;
+	inet->inet_dport = usin->sin_port;
+	sk->sk_state = TCP_ESTABLISHED;
+	inet_set_txhash(sk);
+	inet->inet_id = jiffies;
+
+	sk_dst_set(sk, &rt->dst);
+	err = 0;
+out:
+	release_sock(sk);
+	return err;
+}
+EXPORT_SYMBOL(ip4_datagram_connect);
+
+/* Because UDP xmit path can manipulate sk_dst_cache without holding
+ * socket lock, we need to use sk_dst_set() here,
+ * even if we own the socket lock.
+ */
+void ip4_datagram_release_cb(struct sock *sk)
+{
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct ip_options_rcu *inet_opt;
+	__be32 daddr = inet->inet_daddr;
+	struct dst_entry *dst;
+	struct flowi4 fl4;
+	struct rtable *rt;
+
+	rcu_read_lock();
+
+	dst = __sk_dst_get(sk);
+	if (!dst || !dst->obsolete || dst->ops->check(dst, 0)) {
+		rcu_read_unlock();
+		return;
+	}
+	inet_opt = rcu_dereference(inet->inet_opt);
+	if (inet_opt && inet_opt->opt.srr)
+		daddr = inet_opt->opt.faddr;
+	rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr,
+				   inet->inet_saddr, inet->inet_dport,
+				   inet->inet_sport, sk->sk_protocol,
+				   RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
+
+	dst = !IS_ERR(rt) ? &rt->dst : NULL;
+	sk_dst_set(sk, dst);
+
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(ip4_datagram_release_cb);
-- 
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